Vacuum cleaner attachment for the wet cleaning of surfaces

ABSTRACT

Vacuum cleaner attachment (1) for the wet cleaning of surfaces (20), in particular of vertical surfaces, having a liquid applicator (21), a suction channel (28) having a mouth (15) and a cleaning element (19), the liquid applicator (21) being arranged, for the purpose of continuous working, for the continuous supply of liquid. A liquid supply tank (23) for supplying the liquid applicator (21) is disposed in the vacuum cleaner attachment (1), the liquid applicator (21) being supplied with the liquid by means of capillary action.

FIELD AND BACKGROUND OF THE INVENTION

The invention relates to a vacuum cleaner attachment for the wetcleaning of surfaces, in particular of vertical surfaces, having aliquid applicator, a suction channel having a mouth and a cleaningelement.

In addition to the usual air vacuum cleaners, appliances are also knownwhich can apply liquid, in particular cleaning liquid, and suck it backup in one operation. However, these are suitable only for the cleaningof hard floors. Such wet cleaning, which is performed in one operation,is not known for the cleaning of hard surfaces such as window panes, forexample. In order to clean surfaces of this type, appliances are offeredwhich have separate fresh water and dirty water tanks. Cleaning,including drying, takes place in this case in several steps. Firstly, bymeans of a pump and a spray nozzle, a cleaning solution is sprayed ontothe hard surface, such as a window pane, in a first operation. Thiscleaning solution is distributed using a special sponge in a secondstep. This is followed, in a further final operation, by sucking up thedirty mixture using a suction nozzle, which is connected by means of asuction hose to a blower. What is disadvantageous in this arrangement isthat continuous operation is not made possible. This is associated withdisadvantages, in particular with regard to the improvement of walls.

SUMMARY OF THE INVENTION

An object of the present invention is to configure a vacuum cleanerattachment of the type in question for the wet cleaning of surfaces inan improved manner in such a way that, even if the appliance is used onvertical surfaces or, furthermore, even on surfaces whose surface normalvectors have a non-vanishing component in the direction opposite to thegravitation vector, such as sloping skylights or ceilings, the cleaningof the surface and the sucking up the cleaning liquid is performed inone operation.

On the basis of the arrangement in accordance with the invention, avacuum cleaner attachment is provided which enables continuous workingon surfaces, in particular vertical surfaces. This is achieved in thatfor the purposes of continuous working the liquid applicator is arrangedfor the continuous supply of liquid and the mouth of the suction channelis located downstream of the liquid applicator, relative to anapplication direction, the cleaning element being disposed in the regionof the liquid applicator or between the liquid applicator and thesuction channel. By this means, even vertical surfaces, in particularhard surfaces, such as window surfaces, can be cleaned in one operationin an advantageous manner. As a result of the fact that the liquidapplicator is arranged for the continuous supply of liquid, theappliance according to the invention can be employed irrespective of anyinclination of the surface to be cleaned and thus even in the case ofvertical surfaces. Furthermore, working overhead is also made possiblehereby. While working on the surface, liquid is continuously transferredto the surface by means of the liquid applicator, a cleaning of thesurface being first effected by means of the cleaning element and asucking up of the dirty mixture in the region of the suction channelbeing effected directly subsequently in the course of one movement ofthe appliance in one processing direction.

In this case, a configuration is preferred in which the liquidapplicator is supplied with the liquid by means of capillary action. Asa result of this configuration, active components for the application ofthe cleaning liquid can be dispensed with. Active components are knownin the form of pumps and spray nozzles, these constructions having thedisadvantage that, as the result of spraying the cleaning solution on,only a non-uniform moistening of the surface to be cleaned is effected.Furthermore, in this case, other regions, including, for example, thewindow frames in the case of cleaning windows, are concomitantly andinadvertently also sprayed. Furthermore, in the case of the known priorart, it has transpired that the cleaning solution runs down in dropletsor else as a stream in the case of vertical and sloping surfaces, suchas for example window surfaces. In the case of the invention specified,this is improved in an optimum way by the capillary transport. Here, auniform application of cleaning agent to the surface is effected withouta pump or other electro-mechanical or electronic means. The cleaningmedium, preferably water, alcohols or surface-active substances, isapplied to the surface to be cleaned, by means of the liquid applicator,in such quantities as, on the one hand, ensure a good cleaning effectbut, on the other hand, prevent flow caused by gravity. According to theinvention, the amount needed in this case is around 2 to 10 g water persquare metre of hard surface. The invention thus allows large hardsurfaces to be cleaned reliably with very small amounts of cleaningmedium.

In a further embodiment of the subject-matter of the invention,provision is made that, with respect to the application area, the liquidapplicator is subdivided into substructures. This subdivision ispreferably carried out in such a way that a continuous liquidapplicator, preferably extending over virtually the entire width of thevacuum cleaner attachment, is approximated. The substructures may beformed, for example, in a honeycomb or triangular shape or elserectangular or circular shape. In this case, an arrangement is preferredin which the liquid applicator comprises a tuft of bristlesaccommodating a specific supply of liquid. The said tuft of bristles maybe formed continuously in the form of a strip of tufts of bristles, thatis to say over virtually the entire width of the vacuum cleanerattachment. However, as already mentioned, substructures in the form ofhoneycomb or triangular arrangements of tufts of bristles are alsoconceivable. The application of cleaning agent to the surface to becleaned is effected by the capillary interstices of the tufts ofbristles. In this case, however, cleaning agent is delivered only whenthe tufts of bristles have contact with a surface, for example with awindow surface. If the bristles project beyond an underside of thevacuum cleaner attachment, then provision can be made for the bristlesin this region to be clamped around by a separate bristle holder, whichprevents the bristles from fraying. It has been proven to beparticularly advantageous for a tuft of bristles to consist of bristleswhich include an angle of about 30-60° with the surface to be cleaned.What is achieved by this is that, as a result of the arrangement of thebristles selected obliquely in relation to the surface to be cleaned,the said bristles adapt to the surface to be cleaned over virtually theentire bristle surface by means of slight lateral bending and thuscompensate, for example, for production tolerances and irregularities onthe surface to be cleaned.

The supply to the liquid applicator, in particular to the tufts ofbristles, is performed in a preferred arrangement by the liquidapplicator being disposed in a capillary store, delivery from thecapillary store being effected by capillary action. As alreadymentioned, the invention permits reliable cleaning of large surfacesusing very small amounts of cleaning medium. This therefore makes itpossible to store the required quantity of cleaning medium in arelatively small tank, such as a capillary store. In this case, anembodiment is preferred in which the capillary store can hold ready 30to 150 ml of cleaning liquid. In order to ensure the ability of thecapillary transport to function in any position of use, the capillarystore is equipped with a transfer medium which at any time has contact,at least locally, with the cleaning medium, that is to say the tufts ofbristles of the liquid applicator. According to the invention, thetransfer medium is to be arranged in terms of its wetting properties andgeometry in such a way that the capillary transport from the capillarystore to the surface to be cleaned takes place in the desired amount.The necessary adaptation is effected, according to the invention, by theselection of suitable materials, their surface treatment and thegeometric configuration. In this case, an arrangement is preferred inwhich the capillary store consists of wadding, which ensures acontinuous supply of cleaning liquid to the tufts of bristle, caused bythe capillary action, in any position of the vacuum cleaner attachment.According to the invention, provision may furthermore be made for themouth of the suction channel to be slit-like in form. It is preferred toconnect the vacuum cleaner attachment to a commercially available vacuumcleaner.

In order to clean hard surfaces, in particular vertical surfaces, thevacuum cleaner is switched on, after which cleaning of the hard surfacecan be effected. During the cleaning operation, cleaning liquid isapplied to the surface to be cleaned by means of the applicator andconducted away again via the suction channel in the same operation. Inthis case, in a preferred form, the mouth of the suction channel has awidth which corresponds to the width of the liquid applicator, inparticular to a strip of tufts of bristles. In order to ensure reliabletransport of the dirt/cleaning suspension, and to provide residue-freedrying of the surface to be cleaned, according to the invention airvelocities from 30 to 90 m per second are developed in the suctionregion. To this end, it is advantageous to configure a flow channel insuch a way that the abovementioned local flow velocities are establishedwith only low air volume flows of 3 to 15 l per second, preferably 1.5to 7 l per second. According to the invention, the negative pressureproduced at the mouth of the suction channel can be used for the purposeof supporting the capillary transport of the cleaning medium out of thecapillary store. As already mentioned, the suction channel or the mouthof the suction channel is arranged downstream, in the working direction,relative to the liquid applicator. In order to make it possible to cleansurfaces in two directions at right angles to the vacuum cleanerattachment longitudinal edge, the attachment may be formed to besymmetrical with respect to the liquid applicator, in particular thestrip of tufts of bristles, that is to say provided with a secondsuction channel mouth. In order to ensure optimum cleaning of surfaces,provision is furthermore made for the cleaning element to define an edgeof the mouth of the suction channel.

To this end, the cleaning element is defined in the region between theliquid applicator and the suction channel. In order to support thecapillary transport of the cleaning medium out of the capillary store,caused by the negative pressure produced at the mouth of the suctionchannel, it is further proposed that the cleaning element be providedwith movable or local openings. It is preferred for the cleaning elementto comprise a sealing element with a cleaning nonwoven fabric fitted toit. The latter has a large mechanical interaction with the surface to becleaned. Alternatively, the cleaning element may also comprise a sealingelement with fitted bristles, felt or the like. However, in this case itis essential that a water-repellent material is used. The cleaningnonwoven fabric or the like is preferably configured in such a way thathigh shear forces are exerted on the dirt to be detached. In addition,the sealing element of the cleaning element seals the suction channelrelative to the liquid applicator or to the tufts of bristles,respectively. The delivery of air is effected only in the region of thecleaning nonwoven fabric or the like, only a small air gap beingprovided during operation between sealing element and surface to becleaned in the region of the cleaning nonwoven fabric or the like. Thisleads to an increase in the air velocity in this region. In order toform a suction space, it is proposed that a further edging, of the mouthof the suction channel, located downstream in the processing direction,consists of a lip that is impermeable to air. The latter may be formedas a rubber lip which, during a working operation on surfaces, draws offthe cleaning agent/dirt mixture from the surface. As a result of thehigh air velocity in the suction channel, the mixture is transportedaway through the mouth of the suction channel, this counteracting anydripping of dirty water from the vacuum cleaner attachment after thevacuum cleaner has been switched off.

Furthermore, provision may be made for the mouth of the suction channelto consist of a multiplicity of individual suction channel sections. Asalready mentioned, one type of arrangement consists of a drawing-offrubber, resting continuously on the surface to be cleaned, in the formof the air-impermeable lip, which at the same time forms a limit for thesuction space on that side facing towards the cleaning element.According to the invention, it is proposed that from a main suctionchannel located in the interior of the nozzle, over the entire nozzlewidth, smaller spur channels in the form of suction channel sectionslead from the main channel directly to the draw-off rubber or to theair-impermeable lip. The spur channels effect immediate drying of thelip, by which means water streaks are prevented in the event of renewedplacing of the lip, for example on window panes. Furthermore, a suctionof this type improves the pick-up of water by the suction at low airvolume flows as a result of very high air velocities in the suctionchannel sections, because of the small cross-sections. In this case, itproves to be particularly advantageous for a suction channel section tobe partially bounded by the lip. For instance, the spur channelsmentioned may be formed in such a way that they are provided in the formof comb-like grooves in the region of the bottom of the nozzle housing,open at the edge. In order to form spur channels, the spur channels arebounded on one side by the lip. Furthermore, according to the invention,it is proposed that the suction channel sections be arranged runningobliquely such that they run at an angle towards the suction channel.This is advantageous from the point of view of flow mechanics, inparticular if, as preferred, the axes of the suction channel sectionsintersect at a point which in turn lies on a central axis of the suctionchannel. In this case, this point of intersection may lie in the regionof the mouth of the suction channel.

However, a construction is preferred in which the point of intersectionis provided outside the mouth of the suction channel, in the region ofthe suction channel. What proves to be critical here is, in particular,the operation of setting down a rubber lip, in particular theabovementioned air-impermeable lip, for example at the edges in windowframes, since here the rubber lip is partially severely bent. Theconsequence of this is that the cleaning liquid is in certaincircumstances not completely drawn off from the pane. As a result,streaks can form at these points. According to the invention, thisproblem is solved in that the lip is formed as a double lip.

Accordingly, the first lip is followed by a second lip--as seen in theworking direction. In this case, the arrangement is such that the outerlip consists of a material which is softer than the inner. Alsopreferred here is a rubber lip which is very flexible and which, becauseof its downstream disposition, still rests on the pane even during adrawing-off operation, for example in the region of a window frame. Inthis case, the outer lip is to be fitted to the first lip in such a waythat the latter does not rest on the surface to be cleaned, inparticular the pane, during a normal drawing-off operation, and drawsoff the pane only in the event of a bending down of the attachmentappliance, for example at a window frame. This is achieved in that theouter lip is formed to have a greater spacing from the surface to becleaned in such a way that, during a normal cleaning operation, the saidlip does not come into contact with the surface to be cleaned. In orderto reduce or even eliminate any remaining residual amounts of water, itis proposed to configure the air-impermeable lip in the contact regionwith the surface to be cleaned in such a way that residual water istransported in an optimum way towards the suction channel and isentrained from there by the air volume flow.

To this end, it is proposed that the lip has, on its side facing theliquid applicator, channels running in the width direction of the lip,which channels widen in their cross-section towards the suction channel.These channels are preferably arranged in the contact region of the lipwith the surface to be cleaned. These channels are, for example,wedge-shaped in plan view, the depth--starting from the tip of thewedge--being enlarged towards the broad side of the wedge. As a resultof this form, locally different capillary pressures are achieved, withthe result that any residual water is transported as far as the suctionchannel as a result of the pressure gradient. In an advantageousdevelopment of the subject-matter of the invention, provision is madefor a residual water wiper to be provided further downstream of the lip.The said wiper picks up any residual water remaining on the surface whenthe cleaning is completed. This is effected automatically by thelifting-off operation of the vacuum cleaner attachment effected at theend of the wiping operation. The residual water wiper preferablyconsists of a commercially available, highly water-absorbent porousmaterial, in which residual water is sucked up by capillary action. Inthe case of particularly stubborn contaminations or in other cases inwhich an increased amount of cleaning agent has to be applied to thesurface to be cleaned, it is conceivable to employ the negative pressurepresent in the suction channel in order to increase the cleaning agentvolume flow in the liquid applicator. For instance, provision may bemade for an appliance part located between the mouth of the suctionchannel and the liquid applicator to be arranged to be displaceable insuch a way that a suction channel cross-section acting on the liquidapplicator can be formed or enlarged.

In the case of a normal mode of operation, as described previously, thesuction channel and the liquid applicator are separated physically fromone another, the cleaning liquid being brought to the surface to becleaned by means of capillary transport. The physical separation may bea displaceable appliance part which, in order to increase the cleaningagent volume flow in the liquid applicator, can be moved in such a waythat the suction channel cross-section is enlarged in the direction ofthe liquid applicator. In a preferred arrangement of the subject-matterof the invention, provision is made to this end that the cleaningelement disposed between the mouth of the suction channel and the liquidapplicator is formed as a displaceable appliance part. This cleaningelement provides the physical separation in the usual way. If required,this cleaning element may preferably be displaced by the user, forexample by actuating a button or a slide. As a result of thedisplacement, physical separation between the suction channel and,respectively, the suction channel opening and the liquid applicator isremoved, so that a negative pressure with respect to the environmentprevails at the latter, as a result of which more cleaning liquid isconveyed through the capillary applicator. It is proposed that theliquid applicator, the cleaning element and the mouth of the suctionchannel be arranged in a pivotable working holder. This constructionpermits the vacuum cleaner attachment to be handled very easily. Optimaladaptation of the suction surface to the physical arrangement of thesurface to be cleaned is thus ensured. Furthermore, it is provided thatthe end faces of the liquid applicator and of the cleaning element andthe end edge of the lip lie on one plane. In order also to connect thevacuum cleaner attachment according to the invention to commercialvacuum cleaners, according to the invention it is proposed that thesuction channel run through a filter in order to filter sucked-up liquidout of the sucked-up air.

In this filter, a separation of dirt, cleaning medium and air takesplace. Accordingly, the dirt/cleaning medium suspension is separated inthe filter. An air stream, which is free of condensed material and atthe same time may carry small quantities of solid particles with it,flows out from the vacuum cleaner attachment. This filter may bedisposed in a vacuum cleaner connection housing, by which the connectionto a suction hose or the like of a vacuum cleaner is effected. Accordingto the invention, it is proposed that the filter cooperate with astorage medium for filtering out, in order to form a liquid store. Theair stream flowing from the vacuum cleaner attachment to the vacuumcleaner can furthermore be used for the purpose of drying thedirt/cleaning medium suspension, so that the storage medium only storessmall amounts of liquid and can therefore be configured to be small inits dimensions. According to the invention, the liquid store may beformed at least from a porous medium, with the result that the condensedphase is reliably retained, but as a result of the large surface of suchmedia, as much cleaning liquid as possible is transferred into thegaseous form as a result of interaction with the air stream and isentrained. The porous medium, which has capillary properties, mayconsist, for example, of wadding, sponge, clay granules, paper, activecarbon or the like. Preference is given to an arrangement in which thestorage medium has a fibrous material which, as a result of capillaryaction, optionally a tubular configuration of the fibers, sucks up themoisture and releases it through micro-slits only by evaporation.

To this end, the storage medium may consist of textile fibers, whichstore the liquid in microcavities, transport it as a result of capillaryaction and convey it to the surface through microchannels ormicro-openings, where it then quickly evaporates. Since in this case,the relative moisture of the air volume flow delivered lies below thedew point, any danger to the user, for example as a result of electricshort-circuits, is ruled out. The fibrous material is in this case usedin principle as an intermediate store for the liquid. The incoming airvolume flow, mixed with liquid, gives up the entrained moisture to thetextile fibers and leaves the store only with a relative humidity whichis sufficiently low that any danger as a result of short-circuits isavoided. Furthermore, it is provided that the filter is bounded in thesuction direction by a liquid-impermeable membrane. To this end, thefilter is to be configured in such a way that liquid droplets on themembrane are transported away from this membrane into the storage mediumby the capillary action of the storage medium. As a result of the porousconfiguration of the storage medium, the sucked-up air passes throughthe storage medium on labyrinthine paths in such a way that, optionallyby means of filtering out, liquid separation is effected by deflectingthe flow. As has already been mentioned, it is preferred that thestorage medium is an open-pore foam and/or active carbon. However, aconfiguration is also conceivable in which the liquid store is boundedonly by a membrane and does not have any porous storage medium. In orderto rule out completely any danger to the user, the cleaning liquid incondensed form must not pass to live parts of the vacuum cleaner neededfor the suction. This can be achieved in that the suction iscontrollable, actuatable by a specific degree of filling of the liquidstore.

If the filling level of the liquid store exceeds a specific level, thereis then the risk of some liquid passing out of the store into the wasteair stream leading to the vacuum cleaner. Provision may be made here,for example, for a liquid sensor to be disposed at a suitable point onthe attachment, for example directly upstream of the interface to thevacuum cleaner, which sensor interrupts the voltage supply immediatelyupon contact with condensed cleaning liquids. Moisture sensors of thistype are commercially available. A configuration is preferred in which apressure drop established as a result of the degree of filling of theliquid store is used for the closing movement of a valve closing thesuction channel. A valve of this type may, for example, be locateddownstream in the suction direction of the already mentionedliquid-impermeable membrane. This type of configuration has theadvantage that the membrane has to withstand a lower liquid retainingpressure than without a safety valve, since above an adjustable pressuredifference, the safety valve closes and relieves the membrane. As aresult of this configuration, the use of the attachment on virtually allcommercially available vacuum cleaners is made possible. In a furtherarrangement, it is provided that a front side of the valve is used tosupport the membrane at a high degree of filling of the liquid store. Asa result of this configuration, the membrane is mechanically supportedat high liquid pressures. It is further proposed that the closing valvehave a diaphragm base which is loaded on one side with the pressureprevailing upstream of the liquid-impermeable membrane and on the otherside with the pressure of the suction channel.

In an exemplary configuration, provision can be made to this end for thedifferential pressure present at the water-repellent but air-permeablemembrane to be transferred to the elastic diaphragm base by means of apressure balancing channel and a pressure balancing opening. The saiddiaphragm base in turn actuates a plunger which has a sealing cone, forexample made of rubber, provided on it. The sealing cone is held in anopen position during normal operation by means of a tension spring. Assoon as the pressure difference at the water-repellent membraneincreases, for example as a result of a water film on the membrane, thesealing cone closes a passage opening in the region of the suctionchannel, whereby the membrane is relieved. After this, the suction airstream is suppressed, which also indicates to the user that the liquidstore has reached a maximum filling level. Before working further, it isfirst necessary to empty or exchange the liquid store. In order also tooffer the user visual monitoring of the filling level in the liquidstore, provision can be made for a displacing movement of the valve tobe transferred to an indicator in order to display the degree of fillingof the liquid store. As a result of this type of simple mechanicalindicator, for example coupled with the sealing cone, it is possible toindicate to the user that the storage element is now loaded and thatthis is to be exchanged or to be regenerated. In a further arrangementof the subject-matter of the invention, instead of or as a supplement tothe liquid-impermeable membrane, use may be made of an element whichbinds condensed water. To this end, it is proposed that the liquid storeconsist at least partially of a material, such as polyacrylate, whichvaries in the sense of an increase in volume when liquid is taken up.According to the invention, this binding may take place chemically orchemo-physically.

In the preferred embodiment mentioned, the water-binding medium isembedded in a porous cavity. Known water-binding media are, for example,high molecular weight, industrial substances, such as polyacrylate orthe like, but also natural products such as potato starch. Thewater-binding media change their state on contact with condensed waterin the form that these media swell up, so that a large pressure drop isproduced at these and the air volume flow finally comes to a standstillwith increasing amounts of water. By this means, transport of condensedmaterial into the vacuum cleaner is ruled out. In a further arrangement,provision is made for a special flow path to be provided in the swellingmaterial. This can be implemented, for example, by the separate flowpath being formed with alternating directions with a view to enlargingthe surface. As a result of this, a relatively large surface is providedto take up condensed material. It is further proposed that the wall ofthe separate flow path consist partially or completely of the swellingmaterial. For instance, the construction may be selected such that anappropriately shaped, water-impermeable carrier, for example closed porefoam, forms the flow path, the wall of this separate flow path beingcoated with the swelling material. If condensed liquid occurs in theregion of the separate flow path, the increase in volume of thewater-binding medium reduces the gap width down as far as completeinterruption of the volume flow, as a result of which danger to the useris ruled out. In a preferred arrangement of the subject-matter of theinvention, provision is further made for a liquid-impermeable membraneto be located upstream of the swelling material.

The swelling material or the separate flow path equipped with thisswelling material thus forms a safety device, which is locateddownstream of the liquid-impermeable membrane. If, for example as aresult of excessively high liquid pressures in the region of themembrane, condensed media should pass through, these are then picked upin the region of the safety section formed by the swelling material.With increasing amounts of condensed material, the water-binding mediumcloses the suction channel formed by the separate flow path, as a resultof the swelling up. In an advantageous development of the subject-matterof the invention, provision is made for the liquid stored in the storagemedium to be able to be fed back to the liquid applicator. By thismeans, a closed circuit is formed which permits the liquid picked up inthe storage medium to be fed once more to the capillary store in theworking holder, for further capillary transport to the surface to becleaned. For instance, this feeding back may be achieved by the liquidbeing sucked back out of the liquid store into the capillary store. Thesuction capacity of the connected vacuum cleaner is accordingly used tofeed back the stored liquid to the liquid applicator. To this end, it isproposed that a switchable flow connection be provided between that sideof the membrane on the blower side and the capillary store. Thisswitchable flow connection may, for example, be a flexible pipe or thelike, which connection can be closed or opened, or example by a suitableshut-off element. Via this flow connection, in an open position theliquid collected in the liquid store can be sucked back into thecapillary store.

The shut-off element switching the flow connection can be actuated, forexample, by the user, who releases the connection by actuating anappropriate operating element. Furthermore, in order to carry out thesucking back of liquid into the capillary store, a further, preferablyflexible, hose is provided, which is disposed between the liquid storeand the capillary store. This connection can also be switched inparallel to the flow connection, this in order to prevent uncontrolledrunning back of cleaning liquid out of the capillary store into theliquid store. A construction is preferred in which the flow connectionis open in a state in which the suction cleaner attachment is notresting on the surface to be cleaned. The result of this is that, in aposition in which the vacuum cleaner attachment is not in contact withthe surface to be cleaned, the capillary store has applied to it alarger negative pressure than that which prevails in the liquid store,but this occurs only if the appropriate connections are opened, forexample by the user. To this end, as already mentioned, it is proposedthat the releasing be effected by actuating a release switch. In orderto achieve feeding back of the liquid out of the liquid store into thecapillary store by means of suction force, only the appropriateconnections of the flow path and of the liquid path are opened. Thegreater negative pressure now present on the capillary store effects asucking up of the liquid out of the liquid store, through the openconnection, to the capillary store. The open flow connection, which ishere arranged at one end, via which air is sucked in, preferably has anair-impermeable membrane. In order to offer simplified handling of thevacuum cleaner attachment, it is further proposed for a push buttonswitch to be provided on the vacuum cleaner attachment, this switchreleasing the flow connection when lifted off from the surface to becleaned.

This configuration results in more reliable handling of the attachment,since when the appliance is placed on a surface to be cleaned, suitableshut-off elements in the region of the flow connection and, optionally,in the region of a liquid connection, are closed. Putting the appliancein place once more effects an opening of the connections in themeantime, whereby, even in these short periods, at least proportions ofthe stored liquid can be conveyed back. By this means, a closed circuitis formed, as a result of which the cleaning of relatively large areasis made possible for a relatively small capillary store. In this case,provision can be made for the feeding back to be effected via capillarytransport. The latter can be formed by a capillary conductor arrangedbetween the capillary store and the liquid store. In order, inparticular in the case of a construction in which the liquid is suckedback out of the liquid store into the capillary store, to save ashut-off element in the region of the connection between the liquidstore and the capillary store, provision can be made for the capillarystore to be connected to the liquid store via capillary conveying lines.Only in the event of a greater negative pressure prevailing in theregion of the capillary store than in the liquid store is the liquidtransported into the capillary store via the conveying lines.Furthermore, provision can be made for the feeding back to be effectedonly via capillary channels which are suitably configured in such a waythat they establish the pressure difference necessary for the conveying.Here, it is preferred that such conveying takes place only in theperiods in which the user has switched off the appliance.

In order, during the feeding back of stored liquid to the liquidapplicator, to ensure an adequately high filtering of the used liquid,provision is made for the suction air introduction and the liquidfeedback in the liquid store to be physically removed from one anotherto such an extent that the liquid fed back is at least adequatelycleaned of dirt particles carried in the suction air. This means indetail that the cleaning liquid that is sucked into the liquid store andis mixed with dirt particles must firstly pass through a sufficientlylong path through the storage medium, before it can be fed back oncemore to the liquid applicator via the liquid return. According to theinvention, the negative pressure produced at the mouth of the suctionopening can be used in order to feed back the cleaning fluid to thecapillary store of the liquid applicator after the filtering of thedirt, so that a closed circuit is produced and therefore, using smallamounts of cleaning liquid, large hard surfaces can be cleaned. In thiscase, according to the invention, the vacuum cleaner attachment is to beconfigured in such a way that the negative pressure at the mouth of thesuction channel is greater in magnitude for any position of use of thevacuum cleaner attachment than the negative pressure upstream of thestorage medium, plus the pressure drop in the filter and in thecapillary medium. Furthermore, it is proposed that, in order to providethe pivotable arrangement of the working holder, the suction channel inthe region between the working holder and the appliance connectionhousing having the filter is formed by means of a thin, flexible hose orthe like. In order to indicate the take-up capacity of the storagemedium, it is provided that the liquid store be equipped with a liquidlevel indicator.

To this end, a transparent pane may be provided on an upper side of theconnection housing. To this end, the filling level indicator is formedas a capillary sensor. Depending on the liquid charging of the storagemedium, the said sensor can change colour or other optical properties,such as the light reflection. If, by means of the capillary opticalfilling level indicator, complete filling of the liquid store isindicated, then the user is provided with a signal which is intended toinduce the latter to interrupt the cleaning operation and to empty thestore. As an alternative to this, provision can be made for the liquidstore to be equipped with a negative pressure sensor in order toregister the loading state. When a maximum loading of the liquid storeis reached, a water film forms on the membrane provided at the filterend in the suction flow direction, which film effects an increase in thenegative pressure on the suction side of the membrane. This negativepressure is registered by means of the negative pressure sensor, whichautomatically interrupts the sucking up of air and liquid, so that it isalso not possible for any liquid to drip from the vacuum cleanerattachment after the vacuum cleaner has been switched off. In order ingeneral to achieve a further increase in the cleaning effect, provisionmay be made according to the invention for solid additives (spherical,fiber-like particles and the like) to be added to the cleaning medium.In the case of the previously known solutions, one disadvantage is thatthese appliances, following the cleaning of surfaces--when the applianceis removed from the surface--always leave a residue of dirt and moistureon the surface. In order to counteract this, it is proposed according tothe invention that the edge of the mouth of the suction channel becapable of being moved out on one side, to be specific on the sidefacing the liquid applicator, in such a way that, optionally whilsttilting the working holder, the liquid applicator and, optionally, thecleaning unit is lifted off when the mouth of the suction channel isfurther rested on the surface to be cleaned.

If the vacuum cleaner attachment is tilted away from the surface to becleaned before completing the cleaning operation, but not yet removedfrom the surface, then firstly the liquid supply is interrupted bylifting the liquid applicator. In this case, the cleaning unit is alsoadvantageously lifted, as is the sealing lip. Only the mouth of thesuction channel still rests on the surface, that side of the edge of themouth of the suction channel facing the liquid applicator moving outappropriately. The sucking up of residual liquids and dirt can now takeplace, without new cleaning liquid being able to flow subsequently. Inthis case, provision is made for the movable edge of the mouth of thesuction channel to be movable substantially in the suction direction. Inorder to achieve atomization of residual moisture, it is proposed that,when the edge of the mouth of the suction channel is moved out, a frontedge is displaced in such a way that a comb construction comes intoeffect, in order to form closely bounded suction channels. As a resultof this configuration, the air is sucked through the bounded suctionchannels at high velocity, as a result of which residual liquid which isstill on the pane is atomized. This can additionally be improved bysharp flow edges and deflections directly downstream of the comb. Thisatomization of the liquid is further optimized to the effect that themovable edge of the mouth of the suction channel, forming a rear edge,is of comb-like construction. When the working holder is tilted awayfrom the surface to be cleaned, only the two combs of the edges of themouth of the suction channel still have contact with the surface.

The material of the comb-like sealing elements is preferably awater-repellent, commercially available plastics. In a furtherarrangement, provision can be made for the front edge to be pivotablymounted in the working holder. According to the invention, it isproposed that the rear edge be constructed like a plough in order toform closely bounded suction channels. As a result of thisconfiguration, a comb is likewise provided on a rear edge, but this combcomes into effect only when the working holder is tilted away from thesurface, the front edge of the mouth of the suction channel encounteringwith its comb the surface to be vacuumed, as a result of the pivotingmovability. Thus, in the simplest way, the sucking up of residual liquidand dirt is provided when completing the cleaning operation. In adevelopment of the subject-matter of the invention, provision is madefor the liquid applicator to be able to be displaced in relation to thelip in such a way that the liquid applicator can be moved towards oraway from the surface to be cleaned. This configuration also enablesgood handleability of the vacuum cleaner attachment, with optimumadaptation of the suction surface to the physical arrangement of thesurface to be cleaned. As a result of the displaceability of the liquidapplicator in relation to the lip, both the liquid applicator and thelip always remain in contact with the surface to be cleaned in thecourse of the cleaning. In the event that the vacuum cleaner attachmentis placed on at a relatively acute angle to the surface to be cleaned,the engagement of the liquid applicator by the surface to be cleaned hasthe effect that the liquid applicator is pushed back. As a result of thedisplaceability of the liquid applicator, the contact between the liquidapplicator and lip and the surface to be cleaned is also not released inthe course of the cleaning movement, even if the user, in the course ofthis cleaning movement, tilts the vacuum cleaner attachment in such away that a new angle is established between the attachment and thesurface to be cleaned.

The vacuum cleaner attachment according to the invention can accordinglybe employed irrespective of the angle of attack on the surface to becleaned, and thus offers improved handling. To this end, it is furtherproposed that the liquid applicator, together with the capillary store,be displaceable. The liquid applicator and the capillary store areconsidered as a unitary component and are displaced together in order tochange the position in relation to the lip. By this means, complicatedsealing mouldings are dispensed with, which would otherwise be needed ifonly the liquid applicator were displaceable. Furthermore, it proves tobe advantageous for the suction channel to be formed to be static, andfor the liquid applicator, together with the capillary store, to bedisplaceably disposed on the suction channel. In this case, preferenceis given to a configuration in which the suction channel with itssuction channel mouth and the lip are formed as a connected-togethercomponent. The result of this is that the lip and the mouth of thesuction channel are also fixed with respect to the liquid applicator.The suction channel leading away from the mouth of the suction channelis preferably used as a guide element for the displaceable liquidapplicator. In this case, it proves to be advantageous for the liquidapplicator to be able to be pushed back counter to a spring. The latteralways effects automatic resetting of the liquid applicator into a basicposition. The optional displacement is possible only counter to thespring force.

However, this spring force is arranged in such a way that thedisplacement of the liquid applicator and of the capillary store coupledto the latter may be effected without great effort, for example in thecourse of a cleaning movement, by means of a tilting movement of thevacuum cleaner attachment brought about by the user. In a preferredarrangement, provision is made for the spring to be arrangedconcentrically with the suction channel. Provision is furthermore madefor the liquid applicator, optionally including the capillary store, tobe held on the suction channel via a sleeve-like connecting element. Ina preferred configuration, this sleeve-like connecting element enclosesthe suction channel and carries the liquid applicator together with thecapillary store. A spring surrounding the suction channel acts on thesleeve-like connecting element in such a way that the liquid applicator,optionally including the capillary store, is loaded into a frontposition, contacting the surface to be cleaned. In a preferredarrangement, provision is made for the vacuum cleaner attachment to beable to be tilted over an angular range of about 40°, without the lipand the liquid applicator losing contact with the surface to be cleaned.It also proves to be particularly advantageous for a frontmost and/or arearmost position of the liquid applicator to be latchable. In thefrontmost position, which corresponds to a basic position, the liquidapplicator projects evenly beyond the lip. This position can be securedby a latching element, for example acting between the sleeve-likeconnecting element and the suction channel. In this position, only theliquid applicator acts on the surface to be cleaned, this, for example,for the purpose of a first precleaning of the surface, detaching coarsedirt.

During such pre-cleaning, drawing off the surface to be cleaned by meansof the lip is not desired. This configuration results in the possibilityof separate wetting or, respectively, of washing without suction. Afterthe latching connection has been released, the liquid applicator,optionally including the capillary store, can be displaced back counterto the force of the spring arranged concentrically with the suctionchannel, this taking place at most as far as a rearmost position inwhich the lip is arranged evenly in front of the liquid applicator or,respectively, in which the liquid applicator is set back evenly inrelation to the lip. This position is also secured by a latch. In thisrearmost position, only the lip acts on the surface to be cleaned, thisfor example for the purpose of drawing off and sucking up residual waterin regions which are difficult to access, in which regions the liquidapplicator would interfere. This further yields the advantage ofseparate drying, for example of a glass pane following rain. Followingreleasing of the latching connection, the liquid applicator, ifappropriate including the capillary store, moves back once more into thebasic position, which can then optionally be secured by a latch. If thissecuring by a latch is not used, then the liquid applicator is freelydisplaceable counter to the spring force between the basic position andthe hard edge functional position, for the purpose of continuous contactbetween the liquid applicator and lip and the surface to be cleaned inthe course of the cleaning movement. In a development of thesubject-matter of the invention, provision is made for the cleaningelement to consist of a cleaning cloth which is wetted on the rear side.In this case, it proves to be advantageous for the cleaning cloth to betensioned over a capillary device and wetted by this.

In this case, a micro-nonwoven cloth is preferably used. In a preferredarrangement, this capillary device is the liquid applicator, thecleaning cloth being tensioned over the entire length of the capillarydevice, measured transversely to the movement direction of the vacuumcleaner attachment, to be specific in such a way that the cleaning clothis fastened at one end in the region between the capillary device or theliquid applicator and the mouth of the suction channel, and at the otherend on that side of the capillary device facing away from the mouth ofthe suction channel. In this case, the cleaning cloth is preferablytensioned relatively tautly over the capillary device and extendsessentially parallel to the surface to be cleaned, at least in theregion applied to this surface. By contrast with the configurationspreviously described, in the case of this configuration the surface tobe cleaned is not firstly wetted with a cleaning liquid and subsequentlycleaned by the cleaning element which follows in the working direction.In this case, it is rather that the cleaning element or the cleaningcloth is wetted directly on the rear side by the capillary device orliquid applicator, and the detachment of dirt on the surface to becleaned is performed by a directly wetted cleaning element. By means ofthis always wetted cleaning cloth, more severe contaminations and greasecontaminations can also be detached. Furthermore, by means of thisconfiguration, the bristles of the capillary/moisture device can also beprotected. In order to be able to remove even stubborn contaminations,the vacuum cleaner attachment according to the invention may also beprovided with a scraper edge. As has already been mentioned, it may bepossible to trigger the suction as a function of a specific fillinglevel of the liquid store.

If this filling level exceeds a specific level, then there is the riskthat any liquid will pass out of the store into the waste air streamleading to the vacuum cleaner. It has already been proposed to use avalve for this purpose, which interrupts the suction if a filling levelis exceeded. In an alternative arrangement of the subject-matter of theinvention, it is proposed that the valve be held in the open position bya blocking element, which blocking element is actuatable by being loadedwith moisture. When a predetermined filling level in the liquid store isreached or exceeded, the blocking element, which is preferably locateddownstream in the flow direction, is acted on by moisture. As a resultof this, the valve is displaced into a blocking position in order tointerrupt the suction air stream. As soon as the blocking element isfreed of this moisture, it displaces the valve back once more into theopen position. It is thus possible, for example, to provide a blockingelement which expands under the action of moisture and thus displacesthe blocking element into a blocking position and, after the moisturehas been withdrawn, reverts once more into the original position inorder to displace the valve into the open position. However, aconfiguration is preferred in which the blocking element consists of amaterial which takes up moisture and which is compressible in dependenceon taking up a specific amount of liquid. To this end, it is proposedthat the valve be supported via a control element, spring-loaded againstthe blocking element. If the liquid taken up exceeds a predeterminedlevel, then the blocking element is acted on by moisture, which leads toa compressibility of the blocking element. The blocking element yieldsto the spring pressure of the valve, whereby the latter is displacedinto the blocking position. In relation to this configuration, it isfinally proposed that the blocking element consist of a sponge-likematerial.

For instance, a natural sponge can be provided here, which is disposeddirectly downstream of the liquid store. The latter is gradually filledby sucked-up liquid. If the liquid level reaches the transition to theblocking element, then the latter sucks up some of the liquid. Thisloading with moisture has the effect of softening the sponge-likematerial, the latter being compressible in order to displace the valveinto the blocking position. The previously described blocking device canbe used in the case of virtually any types of liquids, such as water,alcohol, acids, etc. Furthermore, this configuration makes it possibleto use such a blocking device for the automatic closing of containerstaking up liquid, in which closure is desired when a specific fillinglevel is reached. If the liquid store is subsequently emptied, thenbecause the sponge-like material dries out, hardening takes place withsimultaneous resetting, which results in the valve being displaced backinto the open position counter to the spring force. It proves to beparticularly advantageous if, as preferred, the safety element can beseparated from the vacuum cleaner attachment. The blocking valve is thenarranged in the mouth region of the suction hose and assumes a blockingposition when the hose is pulled off. As a result, the risk of suckingup liquid directly by means of the suction hose without the attachmentis counteracted, since the blocking valve does not find any stop surfacefor displacement into the open position. Furthermore, the invention isdistinguished by a low weight. This is in particular as a result of thefact that no pumps or the like are necessary.

The construction of the liquid applicator in the form of tufts ofbristles has the further advantage that the bristles have aself-cleaning effect on account of the relative movement in relation toone another. A vacuum cleaner attachment, constructed as above, for thewet cleaning of surfaces has good acoustic and ecologically alignedproperties and, in addition, can be produced cost-effectively. Thevacuum cleaner attachment, in spite of the integration of liquidapplicator, fresh liquid store and used liquid store, including aseparator, is of small overall construction, which results in goodhandleability of the appliance. The size of the appliance attachmentapproximately corresponds to a normal window wiper. Good handleabilityof the appliance is improved, for the purpose of reaching areas locatedfar away, in that it is provided according to the invention that a longhandle, an extension pipe or the like can be fastened to it. To thisend, an ergonomically designed handle is provided, which serves not onlyto accommodate the long handle or the like, but can also be used inorder to clean easily accessible surfaces directly.

BRIEF DESCRIPTION OF THE DRAWINGS

With the above and other objects and advantages in view, the presentinvention will become more clearly understood in connection with thedetailed description of preferred embodiments, when considered with theaccompanying drawings of which,

FIG. 1 shows a cylinder vacuum cleaner provided with a vacuum cleanerattachment according to the invention for the wet cleaning of surfaces,in a reduced perspective illustration,

FIG. 2 shows the vacuum cleaner attachment in a perspective detailillustration,

FIG. 3 shows the vacuum cleaner attachment according to FIG. 2 in a sideview,

FIG. 4 shows a longitudinal section through the vacuum cleanerattachment,

FIG. 5 shows a front view according to arrow V in FIG. 3 of a workingholder of the vacuum cleaner attachment,

FIG. 6 shows an alternative configuration of a liquid applicatorillustrated in FIG. 5, here the applicator being subdivided with respectto the applicator surface into honeycomb structures,

FIG. 7 shows a further alternative configuration, with triangularsegmentation,

FIG. 8 shows a further embodiment of the subject-matter of the inventionin a partially cut-open side view,

FIG. 9 shows the partially broken-open region of FIG. 8 in an enlargedillustration,

FIG. 10 shows the subject-matter according to FIG. 8, but in a positiontilted away from a surface to be cleaned,

FIG. 11 shows a perspective detailed illustration of a front edge of asuction channel mouth,

FIG. 12 shows a further perspective detailed illustration relating tothe rear edge of the mouth of the suction channel, the latter being ableto be moved out,

FIG. 13 shows a further embodiment of the vacuum cleaner attachment,likewise in a partially broken-open side view, in the working position,

FIG. 14 shows a perspective detailed illustration of the rear edge ofthe suction channel mouth in an alternative configuration,

FIG. 15 shows the vacuum cleaner attachment according to FIG. 13 in aposition tilted away from the surface to be cleaned,

FIG. 16 shows an illustration corresponding to FIG. 9, but relating to afurther embodiment,

FIG. 17 shows the section according to the line XVII--XVII in FIG. 16,

FIG. 18 shows a detail enlargement of the region of a sealing lipresting on a surface to be cleaned, viewed on the inside of the lip,

FIG. 19 shows the section according to the line XIX--XIX in FIG. 18, butin a perspective illustration,

FIG. 20 shows a detailed illustration of the illustration according toFIG. 4, but relating to a further embodiment,

FIG. 21 shows an illustration corresponding to FIG. 20, but followingthe displacement of a cleaning element away from the surface to becleaned,

FIG. 22 shows a further detail representation from FIG. 4, showing asafety element arranged downstream of a liquid-impermeable membrane,

FIG. 23 shows a schematic illustration of a further safety element,

FIG. 24 shows, in a further alternative configuration, a safety valvearranged downstream of the membrane,

FIG. 25 shows a schematic illustration of a device for feeding backliquid,

FIG. 26 shows a schematic illustration of a textile fiber in the storagemedium,

FIG. 27 shows a further embodiment of the vacuum cleaner attachment, ina plan view, a liquid applicator and a capillary store being able to bedisplaced axially counter to a spring with respect to a suction channeland a lip,

FIG. 28 shows the vacuum cleaner attachment according to FIG. 27 in aside view, relating to a frontmost latching position of the liquidapplicator and capillary store,

FIG. 29 shows an illustration corresponding to FIG. 28, but relating toa rearmost position,

FIG. 30 shows a further illustration, corresponding to FIG. 28, butrelating to a non-latched position, in which the liquid applicator andthe capillary store are freely axially displaceable with respect to thelip, for an inclination of the vacuum cleaner attachment at an acuteangle to the surface to be cleaned,

FIG. 31 shows an illustration corresponding to FIG. 30, but relating toa further, angled alignment of the vacuum cleaner attachment in relationto the surface to be cleaned,

FIG. 32 shows a further schematic illustration of an alternative safetyelement, in an open position, and

FIG. 33 shows an illustration corresponding to FIG. 32, but relating tothe closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Shown in FIG. 1 is a vacuum cleaner attachment 1, which is connected viaa suction hose 2 to a vacuum cleaner 3. The vacuum cleaner attachment 1is arranged at a handle 4, which is connected at the end to the suctionhose 2. The securing of the vacuum cleaner attachment 1 to the handle 4is performed via a coupling, not shown in more detail. In order toswitch the vacuum cleaner 3, an on/off switch 5 is provided in thehandle 4.

The vacuum cleaner attachment 1 is essentially composed of two housingparts. The first housing part is a coupling housing 6, which can becoupled to the handle 4 of the vacuum cleaner 3. Provided on thiscoupling housing 6, on the side opposite to the coupling end, is aU-shaped carrier 7, for the pivotable mounting of the second housingpart, formed as working holder 8.

The coupling housing 6 is of bevelled construction in the end regionhaving the carrier 7, to be specific at an angle of about 45°. TheU-legs 9 of the carrier 7 are aligned at an angle of about 90° to thesurface formed by the bevel, the carrier 7 projecting beyond thecoupling housing 6 on both sides and running at right angles to the axisof the body of the coupling housing 6. In their free end region, theU-legs 9 have bearing pins 10, which engage into the housing of theworking holder 8.

The working holder 8 is of rectangular shape in cross-section. In abasic position according to FIGS. 3 and 4, the working holder 8 isaligned such that the underside 11 runs parallel to the bevelled surface12 of the coupling housing 6, but at a spacing from the latter.

The bevelled surface 12 of the coupling housing 6 is extended downwards,as can be seen from FIGS. 3 and 4, so that this surface projects beyondthe underside of the coupling housing 6. The carrier 7 is located in theregion of this projection. Accordingly, the working holder 8 alsoprojects beyond the underside of the coupling housing 6, the bearingpins 10 engaging into the end region of the working holder 8 projectingbeyond the coupling housing 6.

The front surface 13, facing away from the coupling housing 6, of theworking holder 8 has a mouth 15 of a suction channel close to the upperside 14, that is to say close to the side facing away from the bevelledsurface 12. The mouth 15 of the suction channel extends over virtuallythe entire width of the front surface 13 and is formed as a slit. At thefront edge 16, facing the upper side 14, of the mouth 15 of the suctionchannel, an air-impermeable lip 17 is associated with the suctionchannel over the entire width. Provided on the rear edge 18, locatedopposite the front edge 16, is a cleaning element 19, in order to edgethe mouth 15 of the suction channel. This cleaning element 19 comprisesa sealing element with a cleaning nonwoven fabric applied to it, whichfabric has a great mechanical interaction with the hard surface 20 to becleaned. Alternatively, the sealing element may also be provided withbristles, felt or the like fitted to it.

Arranged upstream of the cleaning element 19, in the working directionR, is a liquid applicator 21. The latter comprises capillary elements inthe form of bristles 22, applicator 21 extending in the form of a stripof tufts of bristles parallel to the cleaning element 19, to the mouth15 of the suction channel and to the lip 17, virtually over the entirewidth of the working holder 8 (cf. FIG. 5).

The bristles 22 project beyond the front surface 13 of the working older8, the tip of the lip 17, the front surface of the cleaning element 19and the end surface formed by the strip of tufts of bristles lying on acommon plane E.

The bristles 22 or the liquid applicator 21 extends into a liquid supplytank 23, which is bounded by a wall 24 arranged to be aligned inlongitudinal extent in the working holder 8. The bristles 22 in thiscase extend up close to the rear surface 25, with a spacing from thelatter. Provided in the liquid supply tank 23 is a capillary store 26,which preferably consists of wadding. This serves to supply the bristles22 with a liquid 51 in any position of the vacuum cleaner attachment 1.

In order to avoid fraying of the ends of the bristles projecting freelybeyond the front surface 13, a bristle holder 27 is provided, whichclamps around the bristles 22 or the strip of tufts of bristles.

As already mentioned, the wall 24 provided in the working holder 8bounds the liquid supply tank 23. Further defined by this wall is asuction channel 28 which, proceeding from the mouth 15 of the suctionchannel, extends transversely as far as the rear surface 25 of theworking holder 8, at which rear surface 25 a suction channel opening 29is provided at the centre.

Provided on the upper side 14 of the working holder 8, in the end regionfacing the front surface 13, is a residual water wiper 30, consisting ofa commercially available material which absorbs water well, in whichresidual water is sucked up by capillary action. The said griper isaccordingly arranged downstream of the lip 17 in the working directionR. As can be seen in FIGS. 3 and 4, the tip of the lip-like residualwater wider 30 is set back relative to the plane. However, aconfiguration is also conceivable in which the tip lies on the commonplane E.

The bearing pins 10, forming a hinge, by means of which the workingholder 8 is secured to the coupling housing 6 via the carrier 7, areplaced in such a way that the said bearing pins are located in theregion between the lip 17 and the bristles 22 or the liquid applicator21, as close as possible to the front surface 13 of the working holder8.

A flexible suction hose 31, which can follow the pivoting movements ofthe working holder 8 about the bearing pins 10, opens in the region ofthe suction channel opening 29. This suction hose 31 forms a connectionbetween the suction channel 28 and the coupling housing 6. To this end,an opening 32, which is arranged in the upper region of the bevelledsurface 12, is provided in the bevelled surface 12.

The coupling housing 6, which is formed as a hollow body, contains afilter 33, which is likewise provided as a storage medium 34, in theform of an open-pore foam and/or active carbon. On the coupling side,the liquid store 35 formed is bounded by a water-impermeable andcleaning agent-impermeable, air-permeable membrane 36.

The storage medium 34, which has capillary properties, may furthermoreconsist of wadding, sponge, clay granules, paper or else of porous,sintered materials or materials produced by other processes.Furthermore, the storage medium 34 is configured in such a way thatliquid droplets located on the membrane 36 are transported away from themembrane, by the capillary action of the storage medium 34, into thestorage medium 34.

The take-up capacity of the storage medium 34 is monitored with the aidof a capillary-optical filling level indicator 37. Provided to this endon the upper side of the coupling housing 6 is a window 38, behind whichthere is situated a capillary sensor 39 projecting into the storagemedium 34 and changing colour in dependence on the liquid loading.

Alternatively, the loading state may also be registered by means of anegative pressure switch, the negative pressure being registered on thesuction side of the membrane 36. This negative pressure increases if awater film forms on the membrane 36. In this case, the suction of airand liquid is automatically interrupted, with the result that it is alsonot possible for liquid to drip out of the vacuum cleaner attachment 1after the vacuum cleaner 3 has been switched off.

The application of water or cleaning agent to the hard surface 20 to becleaned is effected by the capillary interstices of the bristles 22.However, liquid is only conveyed when the bristles 22 have contact witha surface. The conveying of liquid out of the capillary store 26 islikewise effected by means of capillary action.

The application of liquid and the sucking up of the liquid containingdirt is performed in one operation. The cleaning medium (preferablywater, alcohols and/or surface-active substances) is applied to thesurface 20 to be cleaned by means of the bristles 22 in amounts which,on the one hand, ensure a good cleaning effect but, on the other hand,prevent flow due to gravity. The amount needed for this is, according tothe invention, about 3 to 10 g water per m² of hard surface. This thuspermits large hard surfaces to be cleaned reliably with very smallamounts of cleaning agent. Accordingly, the liquid supply tank 23 mayalso be of relatively small construction, preferably 30 to 150 ml. Afterthe liquid 51 has been applied to the hard surface 20, with the movementof the vacuum cleaner attachment 1 in the working direction R,detachment of dirt by means of the cleaning element 19 is effected. Thelatter is preferably produced from a water-repellent material. Inaddition, the cleaning element 19, which also has a sealing element,seals off the suction channel 28 or its suction channel mouth 15 withrespect to the bristles 22. By means of the lip 17, the cleaningagent/dirt mixture is drawn off from the hard surface 20 and, as aresult of the high air velocity in the suction channel 28, istransported through the suction channel 29 and the flexible suction hose31 into the storage medium 34 (arrows a). Any residual water 35remaining on the hard surface 20 can be picked up automatically by meansof the residual water wiper 30, as a result of the operation of movingthe vacuum cleaner attachment 1 away, which is required at the end ofthe wiping operation.

The negative pressure produced at the mouth 15 of the suction channelmay be used for the purpose of supporting the capillary transport of thecleaning medium out of the liquid supply tank 23. To this end, theamount of cleaning agent to be transported can be varied by theprovision of a sealing element which is movable or is provided locallywith openings between the mouth 15 of the suction channel and the liquidapplicator 21 or the bristles 22.

As has already been mentioned, the suspension of dirt and cleaningmedium is sucked away from the hard surface 20 to be cleaned by means ofthe connected vacuum cleaner 3 into the filter 33 or into the storagemedium 34. Here, separation of dirt, cleaning medium and air takes place(arrows b). Accordingly, the dirt/cleaning medium suspension isseparated. An air stream which is free of condensed material and at thesame time carries small amounts of solid particles with it flows out ofthe vacuum cleaner attachment 1 (arrows c).

The air stream flowing through the filter 33 or the storage medium 34may be used for the purpose of drying the dirt/cleaning mediumsuspension, with the result that the storage medium 34 stores only smallamounts of liquid and can therefore be formed to be small in itsdimensions. The storage medium 34, which consists at least of a porousmedium, reliably holds back the condensed phase. As a result of thelarge surface of the storage medium 34, however, a large amount ofcleaning liquid is transferred into the gaseous form as a result ofinteraction with the air stream, and is entrained.

In order to ensure reliable transport of the dirt/cleaning suspension,and to provide residue-free drying of the hard surface 20, according tothe invention, air velocities of 30 to 90 m per second are realized inthe suction region. To this end, it is advantageous to configure theflow channel in such a way that the above-mentioned local flowvelocities are established with only low air volume flows of 3 to 15 lper second.

Furthermore, there is the possibility of feeding back the liquid storedin the storage medium 34 to the liquid applicator 21 or to the liquidsupply tank 23. This may take place via capillary transport. However, inthis case it is necessary for the introduction of suction air and thefeeding back of liquid in the liquid store 35 to be separated physicallyfrom each other to such an extent that the liquid fed back is at leastadequately cleaned of the dirt particles carried in the sucked-in air.The high negative pressure produced at the mouth 15 of the suctionchannel may be used for this back transport. A closed circulation isformed, whereby large hard surfaces may be cleaned with very smallamounts of cleaning media. The vacuum cleaner attachment 1 is in thiscase to be configured in such a way that the negative pressure in theregion of the mouth 15 of the suction channel is greater in terms ofmagnitude for any position of use of the vacuum cleaner attachment 1than the negative pressure upstream of the storage medium 34, plus thepressure drop in the filter 33, in the used water tank 35 and in thecapillary medium 34.

In order to achieve a further increase in the cleaning effect, solidadditives such as spherical, fiber-like particles and the like may beadded to the cleaning medium stored in the capillary store 26.

As illustrated in FIG. 5, the liquid applicator 21 may be formed as astrip of tufts of bristles, which consists of closely clamped individualbristles 22. Alternative configurations are illustrated in FIGS. 6 and7. Here, the strip of tufts of bristles is subdivided, this subdivisionbeing executed in such a way that a continuous strip of tufts ofbristles is approximated. This is achieved in FIG. 6 by a honeycomb-likearrangement of tufts of bristles 40. In FIG. 7, this is realised by atriangular arrangement of tufts of bristles 41.

Two further embodiments of the subject-matter of the invention areillustrated in FIGS. 8 to 15. The way in which they function isidentical to the embodiment previously described. Here, only alternativeconfigurations of the edge of the mouth of the suction channel areillustrated.

Firstly, with reference to FIGS. 8 to 12, a vacuum cleaner attachment 1is illustrated which has a suction channel mouth 15 of which the edge 42facing the liquid applicator 21 can be moved out. This edge 42 of themouth of the suction channel is arranged downstream in the workingdirection R of the liquid applicator 21 and of the cleaning element 19,and can be moved, for example in the suction direction. To this end, theedge 42 is formed as a strip which is arranged movably in acorrespondingly shaped groove-like receiver 43, which is open in thedirection of the surface to be worked on. Furthermore, compressionsprings 44 are provided in the receiver 43, which effect automaticoutwards displacement of the edge 42, with the result that the edge 42is always in contact with the surface 20 to be cleaned, up to a specificangle of attack of the vacuum cleaner attachment 1. At its free edge,pointing in the direction of the hard surface 20 to be cleaned, the edge42 is of comb-like construction. To this end, tooth-like projections 45are integrally moulded at the marginal edge, between which projections45 clearances are formed, in order to define closely bounded suctionchannels 46 (for this, cf. FIG. 12).

This comb construction of the rear edge 42, preferably consisting of acommercially available, water-repellent plastics, of the mouth 15 of thesuction channel offers improved sucking up of the dirt/cleaning mediumsuspension during cleaning of hard surfaces 20, since the air velocityis increased as a result of the closely bounded suction channels 46. Thefront edge of the mouth of the suction channel is in this case formed bythe air-impermeable lip 17.

In order to remove residual water and dirt from the hard surface 20before completing the cleaning operation, the vacuum cleaner attachment1 is firstly tilted away from the hard surface 20 in such a way that theliquid applicator 21, the cleaning element 19 and the lip 17 lose theireffect. Because of this, the edge 42 moves out of the receiver 43 as aresult of the spring force of the compression springs 44, and continuesto define a rear edge 48 of the mouth 15 of the suction channel, theedge 42 engaging on the hard surface 20 by means of its projections 45.The opposite edge of the mouth 15 of the suction channel is now formedby a front edge 47, likewise of comb-like construction, which isprovided on the lip 17, to be specific on the rear side of the lip 17,as viewed in the working direction R.

As a result of tilting the vacuum cleaner attachment 1, firstly thesupply of liquid is interrupted as a result of lifting the liquidapplicator 21 from the hard surface 20. In this case, the mouth 15 ofthe suction channel continues to engage on the hard surface 20, thiswith its edge 42, which has been moved out, and with its front edge 47,likewise of comb-like construction. By this means, closely boundedsuction channels 49 and 46 are formed both on the front edge 47 and alsoon the rear edge 48 and on the edge 42. As a result of thisconfiguration, the air is sucked through the closely bounded suctionchannels 46 and 49 at high velocity, as a result of which residualwater, which is still on the hard surface 20, is atomized. Thisatomization of residual water can additionally be improved by sharp flowedges and deflections directly downstream of the comb-like constructionsof front edge 47 and rear edge 48. After the atomization of the residualwater, the vacuum cleaner attachment 1 may be removed from the hardsurface 20.

A further embodiment is illustrated in FIGS. 13 to 15. This differs fromthe exemplary embodiment previously described in that the lip 17,together with the comb-like front edge 47 associated with it, is mountedsuch that it can pivot with respect to the rest of the working holder 8,and in that the edge 42 or the rear edge 48 of the mouth 15 of thesuction channel is realised as a static component which, in order toform closely bounded suction channels 50, has a plough-like constructionof the marginal edge pointing in the direction of the hard surface 20.

The comb-like and plough-like constructions of the front edge 47 andrear edge 48 do not come into effect in a normal working position (seeFIG. 13), just as in the exemplary embodiment previously described. Whenthe vacuum cleaner attachment 1 is tilted away in accordance with theposition in FIG. 15, only the comb-like front edge 47 and theplough-like rear edge 48 make contact with the hard surface 20, as aresult of which atomization of residual water also takes place once morehere, caused by the closely bounded suction channels in the region offront edge 47 and rear edge 48.

A further embodiment of the vacuum cleaner attachment 1 according toFIG. 9 is illustrated in FIG. 16. It can be seen that the bristles 22emerging from the capillary store 26 are arranged in such a way thatthey include an angle alpha of about 60° with the surface 20 to becleaned. However, constructions are also conceivable in which an anglealpha of about 30-60° is provided.

The selected arrangement of the bristles 22 in this case proves to beadvantageous to the extent that, in the course of drawing the applianceattachment 1 on the surface 20 to be cleaned, the said bristles adapt tothe surface 20 to be cleaned virtually over the entire bristle surface,as a result of slight lateral bending in the direction opposite to theworking direction R, and thus compensate, for example, for productiontolerances and irregularities on the surface 20 to be cleaned.

Furthermore, an alternative configuration of the mouth 15 of the suctionchannel can be seen. Here, the suction region is formed in such a waythat a multiplicity of suction channel sections 52 in the form of spurchannels proceed from the mouth 15 of the suction channel. These suctionchannel sections 52 are distributed uniformly over the entire appliancewidth or over the entire longitudinal extent of the mouth 15 of thesuction channel, and preferably have a U-shaped cross-section. Thesuction channel sections 52 are formed in the region of a freelyprojecting end of the front face 13, forming the bottom region, U-shapedchannel boundaries being provided thereby on the appliance housing side.

Furthermore, the suction channel sections 52 are bounded by the lip 17,whereby spur channels are formed.

This configuration offers improved suction. This is still furtheroptimized by the suction channel sections 52 being arranged to runobliquely in such a way that they run at an angle towards the suctionchannel 28. This angled run of the suction channel sections 52 can beseen in the cross-sectional illustration in FIG. 17. The suction channelsections 52 are arranged symmetrically about a main axis x--x, withrespect to their inclination, which main axis x--x simultaneously formsthe central axis of the suction channel 28. The inclination of thesuction channel sections 52 is selected such that central axes y of thesections 52 intersect the main axis x of the suction channel 28, thispreferably occurring within the body of the vacuum cleaner attachment.In the exemplary embodiment shown, the axes y of the suction channelsections 52 include an angle of about 30° with respect to the main axisx. However, constructions are also conceivable in which an angle of30-60° is included.

In the course of a cleaning operation, the construction of such suctionchannel sections 52 which, starting from the mouth 15 of the suctionchannel, extend as far as the region of the lip 17, formed as adrawing-off rubber, has the advantage that immediate drying of thedrawing-off rubber or of the lip 17 is achieved, as a result of whichwater streaks are prevented if the lip region of the vacuum cleanerattachment 1 is applied once again, for example on window panes.Furthermore, a construction of this type improves the take-up of waterby the suction at small air volume flows, as a result of very high airvelocities in the suction channel sections 52, on account of the smallcross-sections. Furthermore, the obliquely running arrangement of thesections 52 has the effect of aligning the air volume flow in thedirection of the suction channel 28.

The operation of moving the lip 17 away, for example at edges in thecase of window frames, proves to be particularly critical, since herethe lip 17 is to some extent severely bent. The result of this is thatthe cleaning liquid is not always completely drawn off from the surfaceto be cleaned. As a result, streaks may form at these points, inparticular on window panes.

According to the invention, this problem is solved in that the lip 17 isformed as a double lip.

As can be seen from FIG. 16, the lip 17 is constructed in prolongationof a housing wall 53 bounding the suction channel 28, the lip 17 in turnforming the boundary of the mouth 15 of the suction channel and of thesuction channel sections 52.

Viewed in the working direction R, an outer, second lip 54 is arrangeddownstream of the lip 17, and preferably consists of a material which issofter than the inner, original lip 17. In this case, the arrangement issuch that the outer lip 54 is located at a spacing from the surface 20to be cleaned during a working operation (cf. FIG. 16). The result ofthis is that, during a normal cleaning operation, this lip 54 does notcome into contact with the surface 20 to be cleaned. In the course ofthe operation of removing the vacuum cleaner attachment 1, the latter isangled, as already mentioned, the second lip 54 coming into contact withthe surface 20 to be cleaned and thereby, for example in the region of awindow frame, further additionally drawing off the window pane,

In order to reduce or even eliminate any amount of residual waterremaining on the surface 20 to be cleaned, in a further refinement theair-impermeable lip 17 is provided with channels 55 in the region ofcontact with the surface 20 to be cleaned (cf. FIG. 18). These channelsare provided on the side of the lip 17 facing the liquid applicator 21and accordingly the mouth 15 of the suction channel, and runsubstantially in the width direction of the lip 17. These channels 55have an acute-angled triangular shape in plan view and are arrangedclose to the region of the suction channel opening 29.

The channels 55 are thereby aligned in such a way that their tips arelocated close to the region of contact with the surface 20 to becleaned, so that these tips face away from the main axis x passingthrough the suction channel 28. In cross-section, these channels 55 havea segment shape, the depth increasing from the tip in the direction ofthe main axis x (for this, cf. the perspective illustration in FIG. 19).

As a result of this configuration, in particular as a result of theshape of the channels 55, different capillary pressures are achieved,with the result that residual water 56 is transported by the pressuregradient towards the suction channel 28 and is therefore entrained bythe air volume flow.

The working holder 8 of the vacuum cleaner attachment 1 according toFIG. 4 is illustrated in a further embodiment in FIGS. 20 and 21. It canbe seen that here the cleaning element 19 is arranged to be displaceablein such a way that the cleaning element 19 can be displaced back from anormal position, acting on the surface 20 to be cleaned (see FIG. 20)into a position which enlarges the cross-section of the mouth 15 of thesuction channel (see FIG. 21). To this end, for example, the cleaningelement 19 may be mounted by means of pins in slots 57 and can bedisplaced by the user by means of a handle, not shown. In this case, achamber 58 which can accommodate the cleaning element 19 in adisplaced-back position is provided.

By means of this configuration, in particular in the case ofparticularly stubborn contamination or in other cases where an increasedamount of cleaning agents have to be applied to the surface 20 to becleaned, the negative pressure that is present in the suction channel 28can be used in order to increase the cleaning medium volume flow in theliquid applicator 21. As a result of the displacement of the cleaningelement 19 into the chamber 58 depicted, the spatial separation betweenthe mouth 15 of the suction channel and the liquid applicator 21 isdispensed with, so that at the latter a negative pressure with respectto the environment prevails, as a result of which more cleaning liquidis delivered through the capillary applicator.

It is also conceivable to provide the spatial separation by means ofanother appliance part, which is arranged so as to be displaceable inorder to increase the cleaning agent volume flow.

In order to rule out completely any risk to the user, for example as aresult of electrical short-circuits, the cleaning liquid 51 must notpass in condensed form to live parts of the vacuum cleaner 3 needed forthe suction. According to the invention, this can be achieved in that amoisture sensor is provided at a suitable point on the vacuum cleanerattachment 1, for example directly upstream of the interface to thevacuum cleaner 3, which sensor immediately interrupts the voltage supplyupon contact with condensed cleaning liquid. Moisture sensors of thistype are commercially available.

In a further construction, instead of or as a supplement to theliquid-impermeable membrane 36, use may be made of an element whichbinds the condensed cleaning fluid. This is illustrated in FIG. 22, withreference to an exemplary embodiment.

Here, a safety element 59 is located downstream of the membrane 36 inthe flow direction, this taking place directly in the region of theinterface to the vacuum cleaner 3.

The safety element 59 has a swelling material 61 embedded between twoporous walls 60.

The safety element 59 is part of the liquid store 35, the swellingmaterial 61 being provided in such a way that it changes in the sense ofincreasing volume in the event of taking up liquid. This binding ofcondensed liquids may take place chemically or chemo-physically. Asalready mentioned, in a preferred embodiment, the water-binding medium61 is embedded in a porous cavity. Known, water-binding media are, forexample, high molecular weight, industrial substances, such aspolyacrylate or the like, or else natural products such as potatostarch.

As a result of the filling of the safety element 59 with a swellingmaterial 61, a separate flow path is provided in which--as a result ofthe large surface formed in this way of the swelling material in orderto pick up condensed moisture--a safeguard is provided in order to ruleout completely any risk to the user. Any moisture which passes throughis picked up by the water-binding media, the latter changing their stateon contact with the condensed liquid, in the form of swelling up, withthe result that a large pressure drop is produced at the swellingmaterial 61 and the air volume flow finally comes to a standstill withan increase in the amount of water. By this means, the transport ofcondensed material into the vacuum cleaner 3 is ruled out.

Accordingly, this produces a device which controllably triggers thesuction in dependence on a specific filling level of the liquid store35. In a further embodiment of the subject-matter of the invention, theincrease in volume of water-binding media, in particular swellingmaterial 61, may advantageously be used inasmuch as the air volume flow,which is mixed with condensed moisture, is led through a gap whose wallconsists of water-binding materials.

An arrangement of this type is shown in a schematic illustration in FIG.23. Provided in the region of the suction channel 28 is a core 62 whichcloses the latter and is made, for example, of closed pore foam, whichcore leaves only a separate flow path 63 of alternating direction. Thisextensive alternation of direction of the flow path 63 serves thepurpose of forming a relatively large surface, the wall of the separateflow path 63 consisting partially or, as is preferred, completely of theswelling material 61. The air, which is penetrated by condensedmoisture, flows through the flow path 63, the increase in volume of thewater-binding medium (swelling material 61) reducing the gap width ofthe flow path 63, when condensed liquid occurs, down to a completeinterruption of the air volume flow, as a result of which risk to theuser is also ruled out here.

A configuration of this type may also be connected downstream of thewater-impermeable membrane 36 as an additional safety element.

In order to reduce the liquid retaining pressure at the membrane 36, asafety valve 64 may furthermore be provided, which is located downstreamof the membrane 36 in the flow direction (cf. FIG. 24). To this end, apressure balancing channel 65 is provided which at one end--viewed inthe outflow direction--is connected upstream of the membrane 36 and atthe other end is connected to a pressure chamber 66 provided in theinterior of the suction channel 28. Located inside this pressure chamberis an elastic membrane 67, to which a plunger 68 with a sealing cone 69fitted at the top is secured. The said cone acts in the direction of thewater-impermeable membrane 36 of the liquid store 35. In this case, aconstruction is preferred in which the sealing cone 69 consists ofrubber.

Provided coaxially with the water-impermeable membrane 36, downstream ofthe latter in the flow direction, is a blocking wall 70 which has anaxial opening 71.

Provided between the pressure chamber 66 and the sealing cone 69 is atension spring 72, which surrounds the plunger 68 and which holds thesealing cone 69, together with the plunger 68, in an open position ofthe axial opening 71.

The entry opening of the pressure balancing channel 65 in the region ofthe liquid store 35 close to the membrane 36 is preferably likewiseclosed by a water-impermeable membrane 73. Furthermore, the pressurechamber 66 has a pressure balancing opening 74 in that region of theelastic membrane 67 located opposite the entry region of the pressurebalancing channel 65. As a result of this configuration, the elasticmembrane 67 is loaded on one side by the pressure prevailing upstream ofthe liquid-impermeable membrane 36 and on the other side by the pressureof the suction channel 28.

During normal operation, that is to say at a low or medium filling ofthe liquid store 35, the pressure difference is low, so that the forceof the tension spring 72 leaves the sealing cone 69 in an open position.However, as soon as the filling level of the liquid store 35 approachesa maximum, the pressure difference increases accordingly, for examplebecause a water film forms on the water-impermeable membrane 36. As aresult of this pressure difference, a displacement of the sealing cone69 in the direction of the axial opening 71 takes place, as far ascomplete closure of this opening 71, as a result of which the air volumeflow is interrupted and accordingly the water-impermeable membrane 36 isrelieved (for this, see the dashed illustration in FIG. 24).

In this closed position, the front face of the sealing cone 69 canadditionally serve to support the membrane 36, in order to relieve thelatter further here as well.

This type of configuration has the particular advantage that themembrane 36 has to withstand a lower liquid retaining pressure thanwithout the use of a safety valve, since above an adjustable pressuredifference, the safety valve 64 closes and the membrane 36 is relieved.This provides for the use of the vacuum cleaner attachment 1 onvirtually all commercially available vacuum cleaners, even those whichare not suitable to suck up condensed liquid.

By means of a simple indicator coupled mechanically to the safety valve64, it is also possible to indicate to the user that the liquid store 35is charged to a maximum and that the latter has to be exchanged or hasto be regenerated. To this end, for example--as illustratedschematically in FIG. 24--a pointer 75 may be provided on the sealingcone 69 or else alternatively on the plunger 68, the position of thepointer 75 being able to be seen by the user from the outside through aviewing window 76.

As already mentioned, the filtered liquid may be fed back out of theliquid store 35 to the capillary store 26. An exemplary configuration isillustrated in FIG. 25.

To this end, on the exemplary embodiment of the vacuum cleanerattachment 1 already explained in FIG. 20, a switchable flow connection77 in the form of a flexible hose is provided. This flow connection isconnected between the capillary store 26 and that side of the membrane36 which faces the suction blower or faces away from the liquid store35. A water-impermeable seal 78, optionally in the form of a membrane,is preferably provided in the region of the entry of the flow 20connection 77 into the capillary store 26. Furthermore, an air filter 79may be provided at the point of connection of the flow connection 77 tothe suction channel 28.

Furthermore, a liquid return connection 80 is provided between the 25capillary store 26 and the liquid store 35, which connection may also bea flexible hose.

By means of this configuration, it is made possible for the filteredliquid to be sucked back out of the liquid store 35 into the capillarystore 26. No further means are thus necessary for refilling thecapillary store 26 with the liquid present in the liquid store 35. Inorder to feed back in this way, it is only necessary to carry out aswitching of the flow connections 77 and 80, for example by the releaseswitches 81 and 82 being actuated by the user. The release switches 8135 and 82 are shown only schematically in FIG. 25.

After the flow connections 77 and 80 have been released, the capillarystore 26 has a greater negative pressure applied to it than prevails inthe liquid store 35. The liquid that is held in the liquid store 35 andhas been filtered is sucked back into the capillary store 26 via thereturn connection 80, the air flow path being deflected with respect toa normal working position via the flow connection 77.

As already mentioned, the releasing of the flow connections may beeffected by actuating release switches. However, it is also conceivablefor a push button switch to be provided in the region of the workingholder 8, which switch releases the flow connection 77 and optionallyalso the return connection 80, on lifting from the surface 20 to becleaned. Accordingly, when the vacuum cleaner attachment 1 is placedonto a surface to be cleaned, corresponding shut-off elements arebrought into a closed position of the flow connection.

Furthermore, the feeding back of liquid from the liquid store 35 intothe capillary store 26 may be effected by the liquid store 35 and thecapillary store 26 being connected via suitable capillary conveyinglines, which implement the pressure difference necessary for theconveying. In this case, preference is given to the conveying beingeffected only in the periods in which the user has switched off theappliance. In the case of such an arrangement, a non-return valve or thelike is advantageously inserted in the region of the capillary conveyinglines.

Shown schematically in FIG. 26, in a much enlarged illustration, is theprinciple of intermediate storing and atomization of the amounts ofwater sucked up. In one configuration, the storage medium 34 maypreferably consist of textile fibers 83 which, on the one hand, storethe liquid 51 sucked up in micro-cavities 84, transport it by capillaryaction and deliver it to the surface 87 through micro-slits 85 ormicro-openings 86, from which surface it can atomize rapidly. As aresult of this configuration, the relative humidity of the air volumeflow delivered remains below the dew point, by which means danger, forexample as a result of electric short-circuits, is ruled out.

Illustrated in FIGS. 27 to 31 is a vacuum cleaner attachment 1 in afurther alternative configuration. What is significant here is that theliquid applicator 21, together with the liquid supply tank 23 and thecapillary store 26, can be displaced axially relative to the lip 17 andthe mouth 15 of the suction channel.

Lip 17, suction channel mouth 15 and the suction channel 28 are formedas a connected-together appliance part, the suction channel 28, just asin the other exemplary embodiments, opening into a liquid store 35provided in the coupling housing 6. In relation to a longitudinal axisof the suction channel 28, the coupling housing 6 is arranged bent at anangle to this channel. The suction channel 28 also forms theconstructional connection between coupling housing 6 and the regionaccommodating the lip 17 and the mouth 15 of the suction channel. Inthis exposed region, the suction channel 28 and its outer wall areformed to be circular in cross-section.

The liquid supply tank 23 accommodating the capillary store 26 islocated on the underside, that is to say arranged in front of the mouth15 of the suction channel in the working direction R, the liquidapplicator 21 being provided on the front side of the said liquid supplytank 23, facing the surface 20 to be cleaned, as also in the previouslydescribed exemplary embodiments. In a plan view according to FIG. 27,the liquid supply tank 23 projects on both sides of the suction channel28 beyond the latter and has a sleeve-like connecting element 90surrounding the suction channel 28 and its outer wall. Via thissleeve-like connecting element 90, the appliance part, essentiallycomprising liquid applicator 21 and capillary store 26, is held on thesecond appliance part essentially having the lip 17 and the suctionchannel 28. As a result of this configuration, the liquid applicator 21,together with its capillary store 23, can be displaced axially along thesuction channel 28.

The connecting element 90 has an actuating knob 91 by means of which itis possible to fix a frontmost position illustrated in FIG. 28 and arearmost position illustrated in FIG. 29. Via this actuating knob 91, asrequired, a latching pin 92 or the like can be introduced intocorrespondingly shaped latching recesses 93 in the connecting element90. The entire latching device is illustrated only schematically in thedrawings.

Provided between the connecting element 90 and a shoulder that ismoulded in the transition region from the suction channel 28 to thecoupling housing 6 is a spring 94 arranged concentrically with thesuction channel 28, which spring has the action of spring-loading thehousing part with the liquid applicator 21 and the capillary store 26 inthe direction of a frontmost position. Accordingly, displacement in thedirection of a rearmost position is performed counter to the springforce.

Furthermore, the cleaning element 19 is formed by a cleaning cloth 95,preferably as a micro-nonwoven cloth, which is tensioned over the liquidapplicator 21. This cleaning cloth 95 is secured, for example held byclamping, to the housing, at one end in the region between the liquidapplicator 21 and the mouth 15 of the suction channel and at the otherend on that side of the liquid applicator 21 facing away from the mouth15 of the suction channel, this holding being illustrated onlyschematically. As can be seen, for example, from FIG. 28, a constructionis preferred in which the other end is secured to an underside of thehousing. Further preferred is a configuration in which the cleaningcloth 95 can be exchanged, for example for cleaning purposes.

In the course of cleaning a surface 20 to be worked on, the cleaningcloth 95 is wetted on the rear side by the liquid applicator 21.

Furthermore, the vacuum cleaner attachment 1 may be provided with ascraper edge, not shown, in order to remove stubborn contaminants.

In order, in a first working step, to begin to dissolve or to begin tosoften coarse contaminants, for example, on the surface 20 to becleaned, the liquid applicator 21, together with the capillary store 26,is displaced into a frontmost position and secured by a latch. Thisposition is illustrated in FIG. 28. It can be seen that the liquidapplicator 21 and, respectively, the cleaning element 19 provided in theform of a cleaning cloth 95 is positioned in front in plane terms of thelip 17, so that the surface 20 can be worked on by the cleaning cloth95, which is wetted on the rear side, without the lip 17 drawing off theliquid applied. This yields the possibility of separate wetting, forexample for washing the surface 20 to be cleaned without suction.

In order to achieve a hard-edge function according to FIG. 29, theliquid applicator 21, together with its capillary store 26, is displacedinto the rearmost position and secured there by a latch. In this case,the liquid applicator 21 and, respectively, the cleaning cloth 95 arealigned so that they are set back in plane terms in relation to the lip17, whereby subsequently the hard surface 20 is contacted only by thelip 17, this for example in order to draw off residual moisture inregions which are difficult to access or in order to dry, for example,glass panes following rain.

The latching means defining the frontmost and the rearmost position mayalso be dispensed with completely according to the invention, with theresult that the appliance part accommodating the liquid applicator 21and the capillary store 26 is freely displaceable on the suction channel28 or on its outer wall. This shows itself to be advantageous in thenormal use of the vacuum cleaner attachment 1, since as a result of thisconfiguration the liquid applicator 21 and, respectively, the cleaningcloth 95 tensioned over the latter, and the lip 17 always rest on thesurface 20 to be cleaned, even when in the course of working in thedirection of the arrow R, the vacuum cleaner attachment 1 may sometimesbe tilted more and sometimes tilted less. The cleaning cloth 95 and theliquid applicator 21 always automatically assume the position contactingthe surface 20, as a result of the spring loading by the spring 94.FIGS. 30 and 31 show two different angular positions of the vacuumcleaner attachment 1 in relation to the surface 20 to be cleaned, inFIG. 30 the attachment 1 including approximately an angle of about 80°and in FIG. 31 including approximately an angle of about 70° in relationto the surface 20. As a result of the configuration according to theinvention, an angular range of about 30-50°, preferably 40°, isprovided, in which there is always contact between lip 17 and cleaningcloth 95 and the surface 20.

Depicted in FIGS. 32 and 33, in a further embodiment, is a safetyelement 95 for the controllable triggering of the suction in dependenceon a specific filling level of the liquid store 35. It can be seen thata blocking element 96 in the form of a sponge-like material, such as anatural sponge, is located downstream of the liquid store 35, which isan open pore foam or the like in the exemplary embodiment shown. Thissponge-like blocking element 96 is in direct contact with the rear end,viewed in the suction direction, of the liquid store 35.

The blocking element 96 is acted on by a valve 64 on that side facingaway from the liquid store 35. The said valve has a sealing cone 97 inorder to interact with a sealing wall 98 on the side of the couplinghousing. Provided in the region of the sealing wall 98 is an axial bore99 for the passage of a control element 100, via which control element100 the sealing cone 97 is supported on the blocking element 96. Inaddition, the sealing cone 97 is acted on in the direction of theblocking element 96 by a compression spring 101.

FIG. 32 shows a position in which the valve 64 is held in an openposition. The valve 64 is supported in this case via the control element100 on the blocking element 96, a passage region for the suction beingformed between the sealing wall 98 and the sealing cone 97. If theliquid store 35 reaches its maximum filling level, then the sponge-likeblocking element is acted on by moisture, which leads to a softening ofthe material and results in compressibility of the blocking element 96.As a result of this moisture-dependent compressibility, it is madepossible for the valve 64 to pass into the closed position, on accountof the spring bias. This position is illustrated in FIG. 33. The controlelement 100 compresses the blocking element 96 in such a way that thesealing cone 97 provided on the control element 100 is engaged againstthe sealing wall 98 in a sealing manner in order to interrupt thesuction.

After the liquid store 35 has been emptied, the blocking element 96decompresses automatically because of the gradual drying out, in sodoing hardens once more and displaces the valve 64 back into the initialposition according to FIG. 32.

The above described configuration of the safety element 95 is alsoconceivable for other containers that take up liquid, which are intendedto be closable automatically when a predetermined filling level isreached.

We claim:
 1. Vacuum cleaner attachment (1) for wet cleaning of a surface(20), particularly a vertical surface, comprising:a liquid applicator(21), a suction channel (28) having a mouth (15) spaced apart from theliquid applicator, and a cleaning element (19) adjacent the liquidapplicator, wherein the liquid applicator (21) is operative forcontinuous supply of liquid to enable continuous working, wherein aliquid supply tank (23) for supplying the liquid applicator (21) isdisposed in the vacuum cleaner attachment (1), the liquid applicator(21) being supplied with liquid from the tank by means of capillaryaction; and wherein the liquid applicator (21) comprises a plurality oftufts of bristles for dispensing liquid from the liquid applicator saidtufts having free ends lying within said supply tank.
 2. Vacuum cleanerattachment according to claim 1, wherein with respect to applicationarea, the liquid application (21) is subdivided into substructures. 3.Vacuum cleaner attachment according to claim 1, wherein the tuft ofbristles comprises bristles (22) which include an angle (alpha) of about30-60° with a front face of the attachment.
 4. Vacuum cleaner attachmentaccording to claim 1, wherein the liquid applicator (21) is disposed ina capillary store (26), conveying of liquid of the applicator beingeffected from the capillary store (26) by capillary action.
 5. Vacuumcleaner attachment according to claim 1, wherein the mouth (15) of thesuction channel has an elongated form.
 6. Vacuum cleaner attachmentaccording to claim 1, wherein the cleaning element (19) defines an edgeof the mouth (15) of the suction channel.
 7. Vacuum cleaner attachmentaccording to claim 1, wherein the cleaning element (19) comprises asealing element, and a cleaning nonwoven fabric fitted thereto, thesealing element serving to seal off the mouth of the suction channelfrom the liquid applicator.
 8. Vacuum cleaner attachment according toclaim 1, wherein an edge region of the mouth (15) of the suctionchannel, located downstream in a direction of application (R), comprisesa lip (17) which is impermeable to air.
 9. Vacuum cleaner attachmentaccording to claim 8, wherein a suction channel section (52) ispartially bounded by the lip (17).
 10. Vacuum cleaner attachmentaccording to claim 1, wherein the mouth (15) of the suction channelcomprises a multiplicity of individual suction channel sections (52).11. Vacuum cleaner attachment according to claim 10, wherein the suctionchannel sections (52) are arranged at an oblique angle relative to afront face of the attachment, and are directed towards the suctionchannel (28).
 12. Vacuum cleaner attachment according to claim 1,further comprising a lip (17) formed as a double lip.
 13. Vacuum cleanerattachment according to claim 1, further comprising a residual waterwiper (30) further downstream of a lip (17).
 14. Vacuum cleanerattachment according to claim 1, wherein the cleaning element (19) isremovably secured between the mouth (15) of the suction channel and theliquid applicator (21).
 15. Vacuum cleaner attachment according to claim1, further comprising a pivotable working holder (8), and wherein theliquid applicator (21), the cleaning element (19) and the mouth (15) ofthe suction channel are disposed in said pivotable working holder (8).16. Vacuum cleaner attachment according to claim 1, further comprising afilter (33) connecting with the suction line for storing material suckedin by the suction line, a fluid conduction line connecting between theliquid applicator and the filter, a bypass fluid conduction lineconnecting with the liquid applicator and bypassing the filter toconnect an air outlet of the filter, and a release switch (81), andwherein releasing of the bypass line is effected by actuating saidrelease switch (81).
 17. Vacuum cleaner attachment according to claim 1,wherein feeding of liquid by the applicator is effected via capillarytransport.
 18. Vacuum cleaner attachment according to claim 1, whereinthe liquid applicator (21) is displaceable together with a capillarystore (26).
 19. Vacuum cleaner attachment according to claim 1, whereinthe liquid applicator is displaceable relative to a housing of theattachment between a frontmost position and rearmost position, theattachment including means for latching the liquid applicator into atleast one of said frontmost and said rearmost position of the liquidapplicator (21).
 20. Vacuum cleaner attachment (1) for wet cleaning of asurface (20), particularly a vertical surface, comprising:a liquidapplicator (21), a suction channel (28) having a mouth (15) spaced apartfrom the liquid applicator, and a cleaning element (19) adjacent theliquid applicator, wherein the liquid applicator (21) is operative forcontinuous supply of liquid to enable continuous working, wherein aliquid supply tank (23) for supplying the liquid applicator (21) isdisposed in the vacuum cleaner attachment (1), the liquid applicator(21) being supplied with liquid from the tank by means of capillaryaction; and wherein the attachment further comprises an inner lip, andan outer lip (54) made of a material which is softer than the inner lip(17), the outer lip being located outside the mouth, and the inner lipbeing located between the outer lip and the mouth.
 21. Vacuum cleanerattachment according to claim 20, wherein the outer lip (54) is formedwith a greater spacing than the inner lip from the surface (20) to becleaned such that, during a normal cleaning operation said outer lipdoes not come into contact with the surface (20) to be cleaned. 22.Vacuum cleaner attachment (1) for wet cleaning of a surface (20),particularly a vertical surface, comprising:a liquid applicator (21), asuction channel (28) having a mouth (15) spaced apart from the liquidapplicator, and a cleaning element (19) adjacent the liquid applicator,wherein the liquid applicator (21) is operative for continuous supply ofliquid to enable continuous working, wherein a liquid supply tank (23)for supplying the liquid applicator (21) is disposed in the vacuumcleaner attachment (1), the liquid applicator (21) being supplied withliquid from the tank by means of capillary action; and wherein theattachment further comprises a lip (17) located adjacent the mouth andhaving, on a side thereof facing the liquid applicator (21), channels(55) running in a width direction of the lip (17), said channelswidening in their cross-section towards the suction channel (28). 23.Vacuum cleaner attachment (1) for wet cleaning of a surface (20),particularly a vertical surface, comprising:a liquid applicator (21), asuction channel (28) having a mouth (15) spaced apart from the liquidapplicator, and a cleaning element (19) adjacent the liquid applicator,wherein the liquid applicator (21) is operative for continuous supply ofliquid to enable continuous working, wherein a liquid supply tank (23)for supplying the liquid applicator (21) is disposed in the vacuumcleaner attachment (1), the liquid applicator (21) being supplied withliquid from the tank by means of capillary action; and wherein anappliance part is located between the mouth (15) of the suction channeland the liquid applicator (21), and is displaceable relative to thesuction channel for establishing a cross-sectional dimensional of thesuction channel.
 24. Vacuum cleaner attachment (1) for wet cleaning of asurface (20), particularly a vertical surface, comprising:a liquidapplicator (21), a suction channel (28) having a mouth (15) spaced apartfrom the liquid applicator, and a cleaning element (19) adjacent theliquid applicator, wherein the liquid applicator (21) is operative forcontinuous supply of liquid to enable continuous working, wherein aliquid supply tank (23) for supplying the liquid applicator (21) isdisposed in the vacuum cleaner attachment (1), the liquid applicator(21) being supplied with liquid from the tank by means of capillaryaction; and wherein the attachment further comprises a filter (33), andwherein the suction channel (28) extends through said filter (33), thefilter (33) filtering sucked-up liquid out of sucked-up air.
 25. Vacuumcleaner attachment according to claim 24, wherein the filter (33)cooperates with a storage medium (34) for filtering out, to form aliquid store (35).
 26. Vacuum cleaner attachment according to claim 25,wherein the storage medium (34) has a fibrous material which sucks upmoisture by capillary action, optionally by means of a tubularconfiguration of fibers (83), and releases it through micro-slits (85)only by evaporation.
 27. Vacuum cleaner attachment according to claim25, wherein the sucked-up air passes through the storage medium (34) onlabyrinth paths such that, optionally by means of filtering out, liquidseparation is effected by deflecting the flow.
 28. Vacuum cleanerattachment according to claim 25, wherein the storage medium (34) isopen-pore foam and/or active carbon.
 29. Vacuum cleaner attachmentaccording to claim 25, wherein the suction is controllable, actuatableby a specific degree of filling of the liquid store (35).
 30. Vacuumcleaner attachment according to claim 25, further comprising a valve(64), and wherein a pressure drop which is established by degree offilling of the liquid store (35) is used for closing movement of thevalve (64) closing the suction channel (28).
 31. Vacuum cleanerattachment according to claim 30, wherein a front side of the valvesupports a membrane (36) at a high degree of filling of the liquid store(35).
 32. Vacuum cleaner attachment according to claim 30, wherein theclosing valve (64) has a diaphragm base which is loaded on one side bypressure prevailing upstream of a liquid-impermeable membrane (36) andon the other side by the pressure of the suction channel (28). 33.Vacuum cleaner attachment according to claim 30, wherein an adjustingmovement of the valve (64) is transferred to an indicator in order todisplay the degree of filling of the liquid store (35).
 34. Vacuumcleaner attachment according to claim 25, wherein the liquid store (35)is made at least partially of a swelling material (61) which changes ina sense of an increase in volume on taking up liquid.
 35. Vacuum cleanerattachment according to claim 34, wherein a separate flow path (63) isprovided in the swelling material (61).
 36. Vacuum cleaner attachmentaccording to claim 35, wherein the separate flow path (63) is formedsuch that it changes direction with a view to enlarging surface. 37.Vacuum cleaner attachment according to claim 35, wherein a wall of theseparate flow path (63) is made partially or completely of the swellingmaterial (61).
 38. Vacuum cleaner attachment according to claim 34,wherein a liquid-impermeable membrane (36) is located upstream of theswelling material (61).
 39. Vacuum cleaner attachment according to claim34, wherein the swelling material (61) is polyacrylate.
 40. Vacuumcleaner attachment according to claim 25, wherein the liquid stored inthe storage medium (34) can be fed back to the liquid applicator (21).41. Vacuum cleaner attachment according to claim 25, wherein the liquid(51) can be sucked back out of the liquid store (35) into a capillarystore (26).
 42. Vacuum cleaner attachment according to claim 41, whereina switchable flow connection (77) is provided between a side of membrane(36) on a blower side and the capillary store (26).
 43. Vacuum cleanerattachment according to claim 42, wherein the flow connection (77) isopened in a state of the vacuum cleaner attachment (1) not resting onthe surface (20) to be cleaned.
 44. Vacuum cleaner attachment accordingto claim 42, further comprising a push-button switch provided on thevacuum cleaner attachment (1), said push-button switch releases the flowconnection (77) when lifted off from the surface (20) to be cleaned. 45.Vacuum cleaner attachment according to claim 41, wherein the capillarystore (26) is connected to the liquid store (35) via capillary conveyinglines.
 46. Vacuum cleaner attachment according to claim 25, whereinintroduction of suction air and feeding back of liquid in the liquidstore (35) are physically removed from each other so far that the liquidfed back is at least adequately cleaned of dirt particles carried in thesuction air.
 47. Vacuum cleaner attachment according to claim 25,wherein the liquid store (35) is equipped with a filling level indicator(37).
 48. Vacuum cleaner attachment according to claim 47, wherein thefilling level indicator (37) is a capillary sensor (39).
 49. Vacuumcleaner attachment according to claim 25, wherein the liquid store (35)is equipped with a negative pressure sensor to register state ofloading.
 50. Vacuum cleaner attachment according to claim 24, whereinthe filter (33) is bounded in suction direction by a liquid-impermeablemembrane (36).
 51. Vacuum cleaner attachment (1) for wet cleaning of asurface (20), particularly a vertical surface, comprising:a liquidapplicator (21), a suction channel (28) having a mouth (15) spaced apartfrom the liquid applicator, and a cleaning element (19) adjacent theliquid applicator, wherein the liquid applicator (21) is operative forcontinuous supply of liquid to enable continuous working, wherein aliquid supply tank (23) for supplying the liquid applicator (21) isdisposed in the vacuum cleaner attachment (1), the liquid applicator(21) being supplied with liquid from the tank by means of capillaryaction; and wherein an edge (42) of the mouth (15) of the suctionchannel is moveable out on one side, specifically on a side facing theliquid applicator (21) such that, optionally during a tilting of aworking holder (8) of the attachment, in event of the mouth (15) of thesuction channel resting further on the surface (20) to be cleaned, alifting off of the liquid applicator (21) and, optionally, of thecleaning element (19), is effected.
 52. Vacuum cleaner attachmentaccording to claim 51, wherein the movable edge (42) of the mouth of thesuction channel is moveable substantially in suction direction. 53.Vacuum cleaner attachment according to claim 51, wherein when the edge(42) of the mouth of the suction channel is moved out, a front edge (47)is displaced such that a comb construction comes into effect to formclosely bounded suction channels (49).
 54. Vacuum cleaner attachmentaccording to claim 53, wherein the front edge (47) is pivotably mountedin the working holder (8).
 55. Vacuum cleaner attachment according toclaim 51, wherein the movable edge (42) of the mouth of the suctionchannel, forming a rear edge (48), is formed like a comb.
 56. Vacuumcleaner attachment according to claim 55, wherein the rear edge (48) isformed like a plough to provide closely bounded suction channels (50).57. Vacuum cleaner attachment (1) for wet cleaning of a surface (20),particularly a vertical surface, comprising:a liquid applicator (21), asuction channel (28) having a mouth (15) spaced apart from the liquidapplicator, and a cleaning element (19) adjacent the liquid applicator,wherein the liquid applicator (21) is operative for continuous supply ofliquid to enable continuous working, wherein a liquid supply tank (23)for supplying the liquid applicator (21) is disposed in the vacuumcleaner attachment (1), the liquid applicator (21) being supplied withliquid from the tank by means of capillary action; and wherein theliquid applicator (21) is displacable with respect to a lip (17) of themouth such that the liquid applicator (21) can be moved towards or awayfrom the surface (20) to be cleaned.
 58. Vacuum cleaner attachment (1)for wet cleaning of a surface (20), particularly a vertical surface,comprising:a liquid applicator (21), a suction channel (28) having amouth (15) spaced apart from the liquid applicator, and a cleaningelement (19) adjacent the liquid applicator, wherein the liquidapplicator (21) is operative for continuous supply of liquid to enablecontinuous working, wherein a liquid supply tank (23) for supplying theliquid applicator (21) is disposed in the vacuum cleaner attachment (1),the liquid applicator (21) being supplied with liquid from the tank bymeans of capillary action; and wherein the suction channel (28) isformed to be static, and the liquid applicator (21), together withcapillary store (26) of the tank, is displaceably disposed on thesuction channel (28).
 59. Vacuum cleaner attachment (1) for wet cleaningof a surface (20), particularly a vertical surface, comprising:a liquidapplicator (21), a suction channel (28) having a mouth (15) spaced apartfrom the liquid applicator, and a cleaning element (19) adjacent theliquid applicator, wherein the liquid applicator (21) is operative forcontinuous supply of liquid to enable continuous working, wherein aliquid supply tank (23) for supplying the liquid applicator (21) isdisposed in the vacuum cleaner attachment (1), the liquid applicator(21) being supplied with liquid from the tank by means of capillaryaction; and wherein the attachment further comprises a spring (94), andwherein the liquid applicator (21) is displacable back counter to saidspring (94).
 60. Vacuum cleaner attachment according to claim 59,wherein the spring (94) is arranged concentrically with the suctionchannel (28).
 61. Vacuum cleaner attachment (1) for wet cleaning of asurface (20), particularly a vertical surface, comprising:a liquidapplicator (21), a suction channel (28) having a mouth (15) spaced apartfrom the liquid applicator, and a cleaning element (19) adjacent theliquid applicator, wherein the liquid applicator (21) is operative forcontinuous supply of liquid to enable continuous working, wherein aliquid supply tank (23) for supplying the liquid applicator (21) isdisposed in the vacuum cleaner attachment (1), the liquid applicator(21) being supplied with liquid from the tank by means of capillaryaction; and further comprising a sleeve-like connecting element, andwherein the liquid applicator (21), includes a capillary store (26)located in the tank, and is held on the suction channel (28) by thesleeve-like connecting element (90).
 62. Vacuum cleaner attachment (1)for wet cleaning of a surface (20), particularly a vertical surface,comprising:a liquid applicator (21), a suction channel (28) having amouth (15) spaced apart from the liquid applicator, and a cleaningelement (19) adjacent the liquid applicator, wherein the liquidapplicator (21) is operative for continuous supply of liquid to enablecontinuous working, wherein a liquid supply tank (23) for supplying theliquid applicator (21) is disposed in the vacuum cleaner attachment (1),the liquid applicator (21) being supplied with liquid from the tank bymeans of capillary action; and wherein the cleaning element (19)comprises a cleaning cloth (95) which is wetted on a rear side facingaway from the surface to be cleaned.
 63. Vacuum cleaner attachmentaccording to claim 62, wherein the cleaning element further comprises acapillary device, and the cleaning cloth (95) is tensioned over thecapillary device and is wetted via the latter.
 64. Vacuum cleanerattachment (1) for wet cleaning of a surface (20), particularly avertical surface, comprising:a liquid applicator (21), a suction channel(28) having a mouth (15) spaced apart from the liquid applicator, and acleaning element (19) adjacent the liquid applicator, wherein the liquidapplicator (21) is operative for continuous supply of liquid to enablecontinuous working, wherein a liquid supply tank (23) for supplying theliquid applicator (21) is disposed in the vacuum cleaner attachment (1),the liquid applicator (21) being supplied with liquid from the tank bymeans of capillary action; and wherein the attachment further comprisesa blocking element, and a valve (64) which is held in an open positionby the blocking element (96), said blocking element (96) beingactuatable by application of moisture.
 65. Vacuum cleaner attachmentaccording to claim 64, wherein the blocking element (96) comprises amaterial which takes up moisture, and which can be compressed independence on a specific amount of liquid taken up.
 66. Vacuum cleanerattachment according to claim 64, wherein the blocking element (96) ismade of a sponge-like material.